An air quality episode will be declared by the Department when pollutant concentrations reach, or are forecasted to reach, and persist, at or above the levels listed below. Pollutant concentrations will be determined by the Department through its analysis of meteorological and ambient air quality monitoring data.
Pollutant | Averaging Period | Advisorya | Alert | Warning | Emergencyb |
CO | 8 hour | NA | 15 ppm | 30 ppm | 40 ppm |
NO2 | 1 hour | NA | 0.6 ppm | 1.2 ppm | 1.6 ppm |
24 hour | NA | 0.15 ppm | 0.3 ppm | 0.4 ppm | |
O3 | 1 hour | NA | 0.2 ppm | 0.4 ppm | 0.5 ppm |
SO2 | 24 hour | NA | 0.3 ppm | 0.6 ppm | 0.8 ppm |
PM2.5 | 1 hour | 80 pg/m3 | NA | NA | NA |
24 hour | 50 pg/m3 | NA | NA | NA | |
PM10 | 1 hour | 385 pg/m3 | NA | NA | NA |
24 hour | 150 pg/m3 | 350 pg/m3 | 420 pg/m3 | 500 pg/m3 | |
Table Footnotes a. The Department may call an Advisory, if it determines, after evaluating the pertinent meteorology, weather conditions and air quality conditions such as visibility, and source parameters such as source type, strength, location and projected duration, that an Advisory is required to protect the public health. b. The Department will only declare an emergency with specific concurrence of Governor. |
Idaho Admin. Code r. 58.01.01.556